视敏度的测量显示了视觉系统在高对比情况下去分辨最小物体的能力,但实际上视野中所能看见的东西包括了各种大小和各种对比度的刺激物。我们看见许多东西并不是由于视敏度高,例如,使用视觉信息去控制姿势,并不需要细小的模式信息。这样,仅从视敏度的测量就很难单独表明视觉系统在日常生活环境中觉察模式的一般能力。一个更好的方式是由测量对比灵敏度函数(CSF)所提供的。通过这个函数可以知道视觉系统对任何东西的灵敏度,从非常粗的线条直至非常细微的空间模式。它是由测量视觉系统觉察不同空间频率正弦波栅条所需最小对比度而得来的,并被画成空间频率的函数。典型成人的对比灵敏度(觉察 Visual acuity measurements show the ability of the visual system to discern the smallest objects at high contrast, but in fact what can be seen in the field of view includes stimuli of various sizes and contrasts. We see a lot of things not because of high visual acuity, for example, the use of visual information to control the posture, does not require a small pattern of information. In this way, it is very difficult to solely indicate the general ability of the visual system to perceive modes in everyday life from the measurement of visual acuity alone. A better way is provided by measuring the contrast sensitivity function (CSF). This function tells you how sensitive the vision system is to everything, from very thick lines to very subtle spatial patterns. It is derived from measuring the minimum contrast required by different spatial frequency sine wave grids by the vision system and is plotted as a function of spatial frequency. Typical adult contrast sensitivity (awareness